Oyster knife



FIG. 1 is a top, left side perspective view of an oyster knife showing our new design;

FIG. 2 is a front elevation view of FIG. 1 ;

FIG. 3 is a rear elevation view of FIG. 1 ;

FIG. 4 is a left side elevation view of FIG. 1 ;

FIG. 5 is a right side elevation view of FIG. 1 ;

FIG. 6 is a top plan view of FIG. 1 ;

FIG. 7 is a bottom plan view of FIG. 1 ; and,

FIG. 8 is a bottom, right side perspective view of FIG. 1 .

The broken lines in the drawings depict portions of the oyster knife that form no part of the claimed design. 

CLAIM The ornamental design for an oyster knife, as shown and described. 